PostgreSQL adapter uses :host instead of :hostname for connection params

[adrianna-chang-shopify]

Motivation / Background

I noticed that the error translation code for the PG adapter looks for a :hostname arg in the conn_params in order to translate to a hostname error. However, the PostgreSQL docs specify that either host or hostaddr should be used, so I'm inclined to think this is an error.

irb(main):001:0> require "pg"
=> true
irb(main):002:0> PG.connect(hostname: "localhost")
/Users/adriannachang/.gem/ruby/3.1.1/gems/pg-1.4.5/lib/pg/connection.rb:714:in `conninfo_parse': invalid connection option "hostname" (PG::Error)
        from /Users/adriannachang/.gem/ruby/3.1.1/gems/pg-1.4.5/lib/pg/connection.rb:714:in `connect_to_hosts'   
        from /Users/adriannachang/.gem/ruby/3.1.1/gems/pg-1.4.5/lib/pg/connection.rb:695:in `new'                
        from /Users/adriannachang/.gem/ruby/3.1.1/gems/pg-1.4.5/lib/pg.rb:69:in `connect'                        
        from (irb):2:in `<main>'                                                                                 
        from /Users/adriannachang/.gem/ruby/3.1.1/gems/irb-1.6.2/exe/irb:11:in `<top (required)>'                
        from /Users/adriannachang/.gem/ruby/3.1.1/bin/irb:25:in `load'                                           
        from /Users/adriannachang/.gem/ruby/3.1.1/bin/irb:25:in `<main>'

Detail

Use :host from connection params instead of :hostname for translating hostname errors in PostgreSQL adapter.

Additional information

Checklist

Before submitting the PR make sure the following are checked:

• This Pull Request is related to one change. Changes that are unrelated should be opened in separate PRs.
• Commit message has a detailed description of what changed and why. If this PR fixes a related issue include it in the commit message. Ex: [Fix #issue-number]
• Tests are added or updated if you fix a bug or add a feature. (If this warrants a test, I'm happy to add one)
• CHANGELOG files are updated for the changed libraries if there is a behavior change or additional feature. Minor bug fixes and documentation changes should not be included.